1. Field of the Invention
The present ivention relates to cutting jigs and fixtures, and more particularly to fixtures used to cut mating mortises and tenons, such as dovetail and pin formations, in workpieces.
2. Discussion of the Prior Art
Various jigs and fixtures used to cut mating mortises and tenons are known.
By way of example, different types of such jigs and fixtures are described in U.S. Pat. Nos. 3,057,383, issued on Oct. 9, 1962 to J. L. Waite; U.S. Pat. No. 3,109,466, issued on Nov. 5, 1963 to B. E. Jones; U.S. Pat. No. 3,834,435, issued on Sept. 10, 1974 to W. M. McCord, Jr.; U.S. Pat. No. 4,168,730, issued on Sept. 25, 1979; and U.S. Pat. No. 4,428,408 issued on Jan. 31, 1984 to Kenneth M. Grisley. Such old fixtures include a horizontal table and a vertical apron and independent clamps for holding two workpieces, such as drawer, box, or bookcase sides are rigidly held at a right angle to each other. A slotted guide member is held against one of the workpieces for guiding a cutting tool, such as a router, so that the cutting bit traces the pattern of the slotted guide member to form a dovetail pattern on the workpieces.
While such known fixtures vary in their capabilities, they seem to be adequate for producing a continuous type dovetail join, i.e., those dovetail joints wherein the mortises defined by the spaces between adjacent tenons are substantially the same width as the tenons. The problem is that it can occur that when using such a continuous type dovetail joint that the middle or edge of a tenon or mortise will be located at the end of a workpiece. This condition leads to an unattractive joint when the two workpieces are assembled with their respective mortises and tenons interlocking, because the first and last tenons of a row will not be equally spaced from the opposite ends of the joint, or less than a complete tenon will be located at an end of a joint.